BENNETT, A. B. J., & NELSON, L. T. (2004). Mathematics for elementary teachers: An activity approach.-- ed.6. McGraw-Hill.

BENNETT, Albert B. Jr, and L. Ted NELSON. Mathematics for Elementary Teachers: An Activity Approach.-- Ed.6. Boston: McGraw-Hill, 2004.

BENNETT, Albert B. Jr, and L. Ted NELSON. Mathematics for Elementary Teachers: An Activity Approach.-- Ed.6. McGraw-Hill, 2004.